The graphics card is also known as video card, graphic controller, graphics accelerator or display card. It is a PCB (printed circuit board) that has three major components. These components are video memory, video BIOS, and graphics processing unit. The graphics card should be changed if it gives a poor performance or if you want more speed options for the computer games. In the first case, you need to verify that it is the reason for the poor performance and not the computer. To do this, use the scan disk or defragmentation options and look for bad sectors on the hard disk. You can also try using other ways to speedup your computer. If they do not work, you can conclude that the lowered performance is due to the faulty working of the card. Once it has been established that the graphics card is responsible for the low speed, you should upgrade it. Some video cards are integrated in the motherboard and some are externally connected to the computer. Older versions of motherboards used a PCI (peripheral computer Interconnect) slot in order to plug-in the video card. Newer versions of computers use the accelerated graphics port (AGP). The latest version of computers use the PCIexpress, which has a speed twice of the AGP slots. The task of upgrading the graphics card in your desktop computer, involves finding out the type of slot in your computer motherboard. If your computer system is relatively quite old, then it is likely that it has a PCI slot. In this case, you have to upgrade related hardware in your computer system, as well. This is because, nowadays, graphic cards compatible only with PCIexpress are available. Additionally, they also render high-speed outputs. The power supply required for a graphics card should also be considered before buying one. The power supply or wattage of the computer must be checked. The power supply ratings range from 350-500W. Also, the available computer RAM must be taken into consideration. Minimum RAM of 512 MB is required. Once all these steps are done, you can buy a new video card. Make sure that you compare all the options available in the market, and choose the one that best suits your needs. To remove the older one and upgrade the computer hardware to a new video card, follow the steps given below:

• If you already have a graphics card, un-install the drivers of the same. Download the drivers of the new one that you've purchased and store them on your computer system.
• Remove the overclocks, usually set to increase the performance of your computer by increasing the clock rate. Set the computer system to its original specifications and turn it off.
• The power cord should be unplugged. Open the cabinet and search for your PCIexpress slot. The PCIexpress slot has a locking clip, which is used to mount the card. Remove the older card and mount the newer one. Store the older card in an anti-static bag, as you can use it as a back-up.
• The computer system can then be switched on, after carefully placing the graphics card in its slot. Start your computer and install the drivers which were downloaded earlier. This ends the up-gradation process and you can start playing games.

The graphics card is basically used to ensure performance, drive a digital screen, and support dual screens for playing games.